Sectional casing



April 22,1930. E. D. LEMMERMAN SECTIONAL CASING me April 10, 1926 2 heets-sheet 2 INVENTOR.

ATTORNEYES Edwarcifl Lmflzermwz BY Y T" a ($14 Patented Ar. 22, 1930 Fries EDWARD n. LEMMEnMAN, or CLEVELAND,- onio s'EoTIonAr. CASING Application filed April 10,

This invention as indicated relates to a sectional casing. More particularly it comprises ai' 'sectional structure formed principally of precastconcrete units and adapted more especially for underground structures for public service such as telephone conduits, sewer, manholes, catch basins, and the like, and meter boxes for Water systems. It is also particularly adaptable for the construction of septic tanks and leaching cesspools for residences.

Reinforced concrete has heretofore been used in the construction of manholes and the like but in most instances such structures 1 have been built in situ and have involved the use of special forms to insure uniformity and economy of construction. This manner of procedure requires extensive equipment because of the differences in height which have to be provided for, and entails much expense and loss of time owing to the fact that building'operations must sometimes be carried on in places difficult of access. I The principal object of the vpresent invention is to obviate the disadvantages referred to and to provide a concrete structure formed of related units, which units maybe precast above the surface of the ground and then fitted together in .proper relation at the point of installation. Where satisfactory condi tions are found the precast units may be turned out in a plant devoted to such work and trans orted to thelpointwhere they are to be use In this manner every structural requirement may be met andgreat economy of manufacture maybe provided for. An-

other object of the invention is to form units of several distinct types certain of which may I be interchangeable with others in order to provide a structure of somewhat different shape than the standard design in order-to accommodate the structure for special purposes. Thus units adapted to form, part of a manhole structure, may be used in connection With a different intermediate portion to form a catch basin or a septictank. Other and further objects of'the'invention will appear in the course of the following description. To theaccomplishment of theforego ing and related ends, said invention, then;

1926. serial no. 101,115.

consists of the means hereinafter fully described and particularly'pointed out in the claims. i

The annexed drawing and the following description set forth in detail one method and several structures exemplifying my invention, such disclosed procedure and structures constituting, however, but several of. various applications of the principles of my invention. V I I I a In said annexed drawings: Fig. 1 is a central vertical sectional View showinga manhole constructed in accordance with the principles of my invention; Fig. 2 isa central vertical sectional view showing a septic tank structure embodying the principles ofmy invention; Fig. 3 is a central vertical sectional view showing a catch basin embodying the principles of my invention; y F ig. 4; is a central vertical sectional view showing an intake basin constructed in ace cordance with the principles of myi'nvention Fig. 5 isa central vertical sectional view showing the method of utilizing the prins ciples of my construction to bring the manhole or other structure to a temporary grade somewhat above an established subgrade; Fig. 6 is a detail view in perspective, showing a method of producing structural units of'an'y desired height; Fig. 7 is a detailed vview partly in section, showing a modified formof step and means for securing the same in position; and Fig. 8 is a perspective view partly in section, showing the method of forming the field cast base.

Asis clearly shown in several figures of t'll Y the drawingthe sectional casing comprises a series of units adapted to be placed one upon the other, preferably with-interengaging end members, to form a concrete structure of chimney-like form and particularly suited for use as manholes, catch basins and the like in 'a sewerage system. 7 As is shown more especially in Figs. l and 8 a base portion 1 is cast in the field at the point of installation of the structure.

The height of the base portion is preferably such as to leave a predetermined space from the upper surface-of the same to the ground to receive a predetermined number of required member is structural units. The base is preferably formed in the manner illustrated. in Fig. 8 of the drawing wherein an adjustable form 2 comprising one or more sheet metal members is bent to cylindrical form and'set down within the cylindrical hole formed to receive a manhole structure. The usual procedure is to excavate a cylindrical hole for the manhole, catch basin or like structure and build the line of sewer to such manhole allowing the sewer pipes 3 to project into the same the distance. The cylindrical form then set in between the ends of lines of sewer pipe and concrete is poured between said mold and the walls of the excavation. The concrete willthus form a cylindrical structure 4 which at its lower margins will. extend over the floor of the excavation. The cylindrical mold may then be withdrawn and the base of the manhole maybe filled in with concrete 5 to the required degree. A troughlike portion 6 is provided in alignment with thesewer pipes to conduct the flow from one pipe to the other and the walls 'Zfadjacent such trough are inclined downwardly and upwardly to a point a slight dlstance above the top l1ne of the sewer pipes to take care of any overflow which may be discharged into-the manhole. Thus adequate space for clearing the sewer pipes is afforded. The upper face of the base member is preferably provided with a groove to receive a rib formed on the under face of one of the precast sections supported thereon.

Immediately above the base portion, a number of precast units 8 of circular outlineare positioned one above the other with their internal walls in direct alignment with the opening in the upper section of the base.

When a sufiicient number of units of circularoutline have been utilized to bring the manhole to a point closely adjacent the surface of the ground, a series'of progressively tapered ring members 9 is used to reduce the diameter of the structure and permit the use of a specially constructed top section 11 above the same. The tapered sections of the manhole are preferably made of slightly less thickness than the lower cylindrical sections but are of approximately twice the vertical height of said lower sections. The top section is I formed at its lower portion of substantially flared outwardly the same thickness as the adjacent tapered sections.-an d its inner wall may be in alignment with the inner walls of'the assembled tapered sections. The outer wall, however, is

K toward thetopto provide a heavyupper portion 12 having a broad top face. Upon said face a flanged metal manhole ring 13 is supported and a suitable cover 14, is engaged'thereover. The upperland lower edges of each of the cylindrical and taperedsections may be formed with grooves and ribs respectively which 'interengage with complementary parts onadjacent members."

The sections in practically every instance are cemented together by suitable material.

As is clearly shown in Fig. 1 of the drawmg, each of the precast sections is provided with a step 15 comprising a metal bar or strap bent to provide a shoulder centrally and adjacent one end, and adapted to be engaged through an aperture in each of the sections to which it is applied. Said shoulders are adapted to bear against the inner and outer walls of the unit and are ofi'set upwardly and downwardly respectively to sustain the thrust applied to the extending tread portion. The method of attaching the steps may vary with the different units but it has been found that by leaving a hole of adequate size at the point where the step is to be positioned, and then, after placing the step in position, filling the balance of the aperture with cement the steps are firmly fixed in place. In addition to the step members serving as a means of ingress or egress for the manhole, they also serve as a point of attachment for one end of a hoisting tackle, the opposite end of which is adapted 'to' be engaged with a temporary tackle engaging element shown in the drawing as a re- 11 ovable eye-bolt 16 which is positionedin each section at a point opposite each step. The aperture through which the eye-bolt is inserted may be filled up with cement after the unit is in place and the eye-bolt has been removed from the structure.

In addition to using the structure as a manhole it has been found that the construction is particularly suited for the building of septic tanks, a form of which is shown in Fig. 2. In such instance the base member 21 is a flat slab, built in situ, formed of substantial thickness and of circular outline and preferably provided with an annular depression 22 adapted to receive arib 23 formed on the lower edge of a precast ring member 24. The ring members are substantially identical in shape with those illustratfirmly secured by cementing or like method.

At a point intermediate of the positions of said pipes, shallow vertical grooves 29 are provided within which the ends of a baffle plate 30 preferably of wood are engaged. The baffle plate prevents direct i'iassage through the tank of the suspended solid matter delivered thereto through saidinlet pipe.

Above the cylindrical portion of the tank a frusto-conical ring member 31 is provided. said member having a sharp inclination and preferably being formed of greater thickn adjacent its base than at its upper edge. Upon the upper edge of said frustoconical membera flat top .member 32 of annular catch basin, a field cast bottom 34 of substan tial thickness is provided upon which a series of cylindrlcal members 35 are built up, said members may have circumferential grooves and ribs as indicated to bring the same into proper register. The upper ring as shown is provided with an aperture at one side with which is connected an outlet pipe 36 indicated by dotted lines which extends upwardly at an angle to a point at which it is desired'to have the water level and'thence substantially horizontally with sutficient inclination for drainage. Above the main body portion a frusto-conical ring member 37 of sharp inclination is mounted in the manner heretofore described and above the same a top section 38 provided with a thickened upper edge of a size to receive and support the metal casting 39 usually employed above a catch basin. I

When the construction is to be used for an intake basin, the cylindrical rings forming the lower body structure, heretofore described in connection with the catch basin, maybe omitted and the frusto-conical section 41 may be mounted directly upon the field cast bottom 42. Said frusto-conical sec tion is provided at one side with an outlet 43 through which drainage may be provided for. A top section 44 of a size and shape substantially similar to the top sections heretofore described is mounted directly upon the frusto-conical section, and a metal casting 45 similar to that used upon the catch basin may be supported thereon.

Where a subgrade has been established it is usually desirable to position the permanent top member 51 at that point, as is shown in Fig. 5, and to set an adjuster ring 52 of cylindrical shape and large diameter, upon the broad upper face of said top member,

preferably maintained in registry by a groove and rib engagement. Above the ad uster rmg, or series of ad uSter rings, if more than one is needed, a temporary top member 53 is provided upon which the metal closure 54 is supported. p 7

The various rings are precast in standard forms and are of standard shapes and sizes.

A single standard form may be employed to cast rings of various height by inserting a movable fiat circular ring 61 at the desired point'between the inner and outer Walls 62,

63,. of the form,asiis shown in: Fig. 6. Where graduated heights of rings'are available, the practice of casting. the base member of the manhole structure at a fixed distance from the surface of the ground may be changed, andthrou'gh the use of proper units the construction may be started: at any desired point irrespective of the exact distance from the surface; 7 I

The forms for the several sections of the casing are preferably formed of metal and may comprise an annular base plate provided with a pair of upstanding ribs spaced from the margins thereof against the lower edges ofa pair of which cylindrical members 63,- are engaged to form the inner and outer walls of the molds. A similar plate (not shown) may be used to form the top of the structure. Intermediate of the walls the annular plate is formed with a depression so as to provide a rib on the under side of a V seetio'nfor'm'ed' in said mold. When the concrete is-placed within the molds an air hammer may be used toinsure the concrete mixture being di'stributed evenly throughout the area in the mold. The inner form member 62. ispreferably formed in two sections'h'aving ii n'vardly' extending cars 64 and a block of wood 65 or similar spacing? member may be interposed between the two sections in order that when the concrete unit is completed the inner mold may be readily withdrawn therefrom by knocking out the wooden blocks and withdrawingeach of the sections in turn.

Instead of forming: the step members in the mani'rer shown in Fig. 1, it may be found desirable to apply a modified form of step memher, as isshown in Fig. 7. Insuch case an aperture is provided through the unit 71 and the shank 72 of an offset step member 73 is inserted therethrough. A washer 74 and nut 75 are then engaged upon the projecting screw-threaded end of the step-member and the off-set or angular portion ofthe step is then drawn against the opposite wall by tightening the nut.

Through the use of the various structural units described, the construction of standardized'concrete structures is a simple mat. ter'. In addition to economies possible through quantity production of. relatively small units, reinforced as desired, there is a very great economy-effected through the dispensing with cumbersome molds necessitated where monolithic concrete structures are made. The units may be precast at a point adjacent the work or in a central plant-and shipped to the point of installation at no greater cost than for they transportation of material for forms for field cast structures.v

her, and the standardization of the units pro vides for a minimum number of forms with adequate selection of parts to meet the re quirements of a large number of structures for special purposes.

\Vhile the invention has been described as applied to the building of structures used a with a sewer system, it is to be understood that the invention is in no way'to be limited to such use and may be applied to many other uses such as the construction of manholes for telephone conduit systems or to meter boxes for water systems.

Other forms may be employed embodying the features of my invention instead of those herein explained, change being made in the form or construction, provided the elements y stated by any of the following claims or the equivalent of such stated elements be employed.

I therefore particularly point out and distinctly claim as my invention:

1. In an'article of the character described, the combination of a field-cast base provided with an upstanding flange portion open at opposite sides to provide an inlet and outlet aperture, said flange portion being provided with a a groove on its upper edge, a series of precast circular sections having ribs and grooves on their respective edges and adapted to interengage with each other, the rib on the lowermost of said sections being seated in the groove in said flanged base, a series of precast tapered sections provided with grooves and ribs on opposite edges and inter- V engaged with each other, the ribs on the lowermost of said edges being received in the grooves on the precast circular sections, and a precast top section formed with a rib on its lower edge being adapted to interengage with the groove upon the uppermost of said tapered sections, said top section being thick- 40 e'ned adjacent its upper edge to provide a supporting surface for a closure.

' 2. In an article of the character described, the combination of a field-cast base provided with an upstanding flange portion,

4,5 said flange portion being provided with a circumferential interlocking element at its upper edge, a series of precast circular sections and precast tapered sections having circumferential interlocking elements on their 1 respective edges and adapted to interengage with each other, the element on the lowermost of said sections being engaged with the complementary element on said flanged base, and a precast top section formed with a circumi ferentiai interlocking element on its lower edge adaptedto interengage with the complementary element upon the uppermost tapered section, said top section being thickenedadj a- 3 cent its upper edge to provide a supporting I surface for a closure.

Signed by me this 3rd day of April, 1926. EDWARD'D. LEMBEEBMAN. 

